We wish to prove, or disprove, the cyclic metabolic pathway of BHT by liver microsomes, i.e., BHT to BHT-hydroperoxide to BHT-hydroxide and back to BHT (Chart I, compounds 1, 2, and 3). We feel this metabolic pathway may explain the mechanism of aromatic oxygenation andantioxidation, and thus also the mode of action of alpha tocopherol. It has been repeatedly shown that hydroperoxides are highly reactive. They may react with cellular constituents. We wish to find out if BHT hydroperoxide will covalently bind to proteins, nucleic acids, etc. It will serve as a model compound to explain certain chemical carcinogenesis, liver damage, adrenal necrosis and many other chemically induced damages. The understanding of BHT metabolism as proposed may serve as a model in the study of estrogen metabolism.